Maybe something like the Yamaha Chord Tracker app?
Here's a demo video https://youtu.be/mnXmLNwUI-o?t=79
(I've started it at 1:19 to where he records a sound file and the app recognizes the chords)
I've never used this app but your post reminded me of it from when I was shopping for a keyboard a while back. BTW, the video mentions PSR-S series, this app is also in DGX660 (the keyboard I considered, and much cheaper than the PSR-S).